Mobile phones are usually assigned to a downtown rate center in order to obtain a better inbound local calling area.
[5] The creation of large numbers of relatively geographically-small rate centers allows relatively short haul connections to be long distance, with the local calling area varying arbitrarily from one portion of the same town to another.
Some tiny place used to be a separate village or used to have a small manual switchboard, but was swallowed by urban or suburban sprawl years ago — yet the rate center (and a restrictive local calling area) still exists.
[8] Often, incumbent carriers will threaten small communities with substantial increases in the monthly cost of an individual line if rate center consolidation expands local calling areas.
The rare exceptions have been small groups of suburbs which each already have the same local calling area; one unified rate center would allow wire-line subscribers to keep existing numbers if they move from one of the communities to another.
These rare efforts normally operate in parallel with other conservation measures, such as number pooling and aggressive reclamation of unused central office codes.